Bump Microsoft.OpenApi from 1.6.12 to 1.6.13

Bumps [Microsoft.OpenApi](https://github.com/Microsoft/OpenAPI.NET) from 1.6.12 to 1.6.13.
- [Release notes](https://github.com/Microsoft/OpenAPI.NET/releases)
- [Commits](microsoft/OpenAPI.NET@1.6.12...1.6.13)

---
updated-dependencies:
- dependency-name: Microsoft.OpenApi
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

src/Kiota.Builder/Kiota.Builder.csproj

@@ -44,7 +44,7 @@
     <PackageReference Include="Microsoft.Kiota.Serialization.Json" Version="1.1.3" />
     <PackageReference Include="Microsoft.Kiota.Serialization.Text" Version="1.1.1" />
     <PackageReference Include="Microsoft.kiota.Serialization.Multipart" Version="1.1.1" />
-    <PackageReference Include="Microsoft.OpenApi" Version="1.6.12" />
+    <PackageReference Include="Microsoft.OpenApi" Version="1.6.13" />
     <PackageReference Include="Microsoft.OpenApi.ApiManifest" Version="0.5.4-preview" />
     <PackageReference Include="Microsoft.OpenApi.Readers" Version="1.6.12" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />